New York Agricultural Experiment Station. 467 



done. In all cases much pains was taken to wet both upper and 

 under surfaces of the leaves. 



Experiments. — About the middle of June the block was sprayed 

 with a solution of whale-oil soap, one pound to seven gallons of 

 water. After waiting two days no beneficial results were appa- 

 rent. The block was again sprayed with whale-oil soap, one 

 pound to four gallons of water. This had the effect of keeping 

 the insects away for a few days, but injured the foliage slightly 

 during one or two warm bright days which followed the applica- 

 tion of the soap. In about six days from this last application the 

 trees were again sprayed, this time with whale-oil soap, one 

 pound to seven gallons of water, with the addition of flowers of 

 sulphur, one ounce to each gallon of solution. This proved much 

 more effectual than either of the other applications. Another 

 application of the soap solution with the sulphur added was made 

 a week later. Although this species of thrips continued abundant 

 throughout the season on other ornamentals in the immediate 

 vicinity of the block of birch, no further injury of a serious nature 

 resulted to the sprayed trees. 



Conclusions. — These experiments indicate that thrips can be 

 held in check by a whale-oil soap solution, one pound to seven 

 gallons of water, with the addition of one ounce of flowers of 

 sulphur to each gallon of the solution when attacking trees simi- 

 lar to the cut-leaved birch. It should be remembered that it is 

 important that the leaves should be drenched on both upper and 

 under surfaces. 



Experiments in Fumigating Nursery Stock. 

 These experiments have only just begun, and hence require but 

 brief mention here. Fumigating nursery stock is usually done 

 for the purpose of killing the San Jos6 scale. If fumigation can 

 be made practical in the large cellars used by nurserymen it will 

 be an inexpensive way to treat a large amount of stock, and a 

 preventive to the spread not only of the San Jos6 scale, but other 

 insects, such as the woolly aphis, bud moth, pistol-case-bearer and 

 other injurious species. Experiments along this line are being 



